[CapROS-devel] IOMMU = GART ??

[Norman H. <no...@ca...>]

I quote from  
<http://developer.apple.com/documentation/Hardware/Developer_Notes/ 
Macintosh_CPUs-G5/iMacG5/index.html>:
To further improve the performance of the AGP bus, the U3L IC supports  
a graphics address remapping table (GART). Because the virtual memory  
system organizes main memory as randomly distributed 4 KB pages, DMA  
transactions for more than 4 KB of data must perform scatter-gather  
operations. To avoid this necessity for AGP transactions, the GART is  
used by the AGP bridge in the U3L to translate a linear address space  
for AGP transactions into physical addresses in main memory.

This sounds like there is a map between the graphics chip and real  
memory.
How common is this today?


Norm Hardy: <http://cap-lore.com>
Nothing has an uglier look to us than reason, when it is not on our  
side.
Lord Halifax